1. Field of the Invention
This present invention relates to a sheet folding apparatus, and more specifically to a device for folding sheets of different formats and depositing the sheets in folded form.
2. Discussion of the Related Art
U.S. Pat. No. 4,701,155 describes an apparatus for folding sheets of drawings in the various A1, A2 or A3 formats which drawings are conventionally provided with a legend in the bottom right-hand corner. Sheets of drawings are fed in the feed path of this known apparatus with an orientation such that the drawing, and hence also the legend, is legible when viewed from a specific side of the feed path. Looking in the direction of the feed, the legend is then situated at the left-hand side of the trailing part of the sheet fed in the longitudinal direction. In the first folding station an A1 sheet is folded four times in the transverse direction, an A2 sheet is folded twice or four times and an A3 sheet is folded twice. A packet thus folded in zig-zag fashion is then fed to the second folding station with the legend situated at the top. In the second folding station the zig-zag folded A1 and A2 sheets are double-folded and the zig-zag folded A3 sheet is passed on without any further folding. The sheets folded in this way are then deposited in a collecting station in a uniform way, i.e. with the legends at the top.
One of the features of this known apparatus is that in order to ensure that folded sheets of drawings are deposited with their legends on the same side, the sheets must always be fed with their longest side parallel to the feed direction, and this is hereinafter referred to as longitudinal feed. In the conventional use of this apparatus for folding sheets delivered by a sheet-processing apparatus such as a copying machine wherein the sheets are separated from a roll in such an apparatus, the use of longitudinal feed on its own has the disadvantage in that a separate roll whose length corresponds to the shorter side of the standard format must be provided for each of the standard formats to be folded. Since, in the case of longitudinal feed, the processing capacity of the apparatus is inversely proportional to the length of the longest side of a sheet of drawing, the known apparatus has the disadvantage that the processing capacity is adversely affected in order to achieve the above uniform deposition.